* The Koch brothers’ Americans for Prosperity are launching a new “$3.5 million attack advertising campaign” targeting three vulnerable Democratic senators and three vulnerable Democratic House members over their support for the Affordable Care Act.

* Though Sen. Mark Udall (D-Colo.) is generally considered a fairly safe bet for re-election, a new Quinnipiac poll shows the incumbent ahead by just three points over far-right Republican Ken Buck, who failed in his first Senate bid in 2010.

* And speaking of Colorado, the same Quinnipiac poll shows Gov. John Hickenlooper (D) leading each of his four Republican challengers by margins ranging from four to six points.

* In Mississippi, PPP shows Sen. Thad Cochran leading Chris McDaniel in a Republican primary by just six points, 44% to 38%, if Cochran seeks re-election.

* In Montana, PPP shows Rep. Steve Daines (R) with a big lead over Lt. Gov. John Walsh (D) in next year’s open U.S. Senate race, 52% to 35%. The PPP report suggested Walsh is at a big disadvantage because of his party, which is unpopular in the state.

* And in fundraising news, the Democratic Congressional Campaign Committee raised about $7 million in October, a record for the DCCC in an off-year October.